code: def test_add_log_item():
      """Test _MockEstimatorMixin.add_log_item behaviour."""
      mixin = _MockEstimatorMixin()
      mixin.add_log_item(1)
      mixin.add_log_item(2)
      assert mixin.log[0] == 1
      assert mixin.log[1] == 2
  
file_path: sktime/sktime/utils/estimators/tests/test_base.py
imports: import pytest
  from pandas.testing import assert_series_equal
  from sktime.classification.base import BaseClassifier
  from sktime.clustering.base import BaseClusterer
  from sktime.datasets import load_airline
  from sktime.forecasting.base import BaseForecaster
  from sktime.forecasting.naive import NaiveForecaster
  from sktime.transformations.base import BaseTransformer
  from sktime.transformations.series.boxcox import BoxCoxTransformer
  from sktime.utils.estimators import make_mock_estimator
  from sktime.utils.estimators._base import _method_logger, _MockEstimatorMixin
label_desc: Use image node_id 2 for calling a global function with example usage: test_add_log_item() without return types